Use map<nodeId, validatorPeer> instead of array; verify validator's signature in commit message processing

benchmark.go

@@ -48,7 +48,7 @@ func getLeader(myShardId string, config *[][]string) p2p.Peer {
 			}
 			socketId := reg.ReplaceAllString(ip+port, "") // A integer Id formed by unique IP/PORT pair
 			value, _ := strconv.Atoi(socketId)
-			priKey := crypto.Ed25519Curve.Scalar().SetInt64(int64(value))
+			priKey := crypto.Ed25519Curve.Scalar().SetInt64(int64(value)) // TODO: figure out why using a random hash value doesn't work for private key (schnorr)
 			leaderPeer.PubKey = crypto.GetPublicKeyFromScalar(crypto.Ed25519Curve, priKey)
 		}
 	}

consensus/consensus.go

@@ -23,8 +23,8 @@ type Consensus struct {
 	bitmap *crypto.Mask
 	// Signatures collected from validators
 	responses map[string]string
-	// List of validators
-	validators []p2p.Peer
+	// map of nodeId to validator Peer object
+	validators map[uint16]p2p.Peer
 	// Leader
 	leader p2p.Peer
 	// private/public keys of current node
@@ -88,10 +88,19 @@ func NewConsensus(ip, port, ShardID string, peers []p2p.Peer, leader p2p.Peer) *
 	}
 
 	consensus.commitments = make(map[uint16]kyber.Point)
+	consensus.validators = make(map[uint16]p2p.Peer)
 	consensus.responses = make(map[string]string)
 
 	consensus.leader = leader
-	consensus.validators = peers
+	reg, err := regexp.Compile("[^0-9]+")
+	if err != nil {
+		log.Crit("Regex Compilation Failed", "err", err)
+	}
+	for _, peer := range peers {
+		socketId := reg.ReplaceAllString(peer.Ip+peer.Port, "") // A integer Id formed by unique IP/PORT pair
+		value, _ := strconv.Atoi(socketId)
+		consensus.validators[uint16(value)] = peer
+	}
 
 	// Initialize cosign bitmap
 	allPublics := make([]kyber.Point, 0)
@@ -106,10 +115,6 @@ func NewConsensus(ip, port, ShardID string, peers []p2p.Peer, leader p2p.Peer) *
 	consensus.bitmap = mask
 
 	// Set private key for myself so that I can sign messages.
-	reg, err := regexp.Compile("[^0-9]+")
-	if err != nil {
-		log.Crit("Regex Compilation Failed", "err", err)
-	}
 	socketId := reg.ReplaceAllString(ip+port, "") // A integer Id formed by unique IP/PORT pair
 	value, _ := strconv.Atoi(socketId)
 	consensus.priKey = crypto.Ed25519Curve.Scalar().SetInt64(int64(value))
@@ -151,6 +156,14 @@ func (consensus *Consensus) signMessage(message []byte) []byte {
 	return signature
 }
 
+func (consensus *Consensus) getValidatorPeers() []p2p.Peer {
+	validatorPeers := make([]p2p.Peer, 0)
+	for _, validatorPeer := range consensus.validators {
+		validatorPeers = append(validatorPeers, validatorPeer)
+	}
+	return validatorPeers
+}
+
 // Reset the state of the consensus
 func (consensus *Consensus) ResetState() {
 	consensus.state = FINISHED

consensus/consensus_leader.go

@@ -5,6 +5,7 @@ import (
 	"encoding/binary"
 	"encoding/gob"
 	"github.com/dedis/kyber"
+	"github.com/dedis/kyber/sign/schnorr"
 	"harmony-benchmark/blockchain"
 	"harmony-benchmark/crypto"
 	"harmony-benchmark/p2p"
@@ -78,9 +79,10 @@ func (consensus *Consensus) startConsensus(newBlock *blockchain.Block) {
 	consensus.blockHeader = byteBuffer.Bytes()
 
 	msgToSend := consensus.constructAnnounceMessage()
-	p2p.BroadcastMessage(consensus.validators, msgToSend)
+	p2p.BroadcastMessage(consensus.getValidatorPeers(), msgToSend)
 	// Set state to ANNOUNCE_DONE
 	consensus.state = ANNOUNCE_DONE
+
 	// Generate leader's own commitment
 	secret, commitment := crypto.Commit(crypto.Ed25519Curve)
 	consensus.secret = secret
@@ -117,7 +119,7 @@ func (consensus *Consensus) constructAnnounceMessage() []byte {
 
 // Processes the commit message sent from validators
 func (consensus *Consensus) processCommitMessage(payload []byte) {
-	//#### Read payload data
+	// Read payload data
 	offset := 0
 	// 4 byte consensus id
 	consensusId := binary.BigEndian.Uint32(payload[offset : offset+4])
@@ -135,13 +137,20 @@ func (consensus *Consensus) processCommitMessage(payload []byte) {
 	commitment := payload[offset : offset+32]
 	offset += 32
 
-	// 64 byte of signature on previous data
+	// 64 byte of signature on all above data
 	signature := payload[offset : offset+64]
 	offset += 64
-	//#### END: Read payload data
 
-	// TODO: make use of the data. This is just to avoid the unused variable warning
-	_ = signature
+	// Verify signature
+	value, ok := consensus.validators[validatorId]
+	if !ok {
+		consensus.Log.Warn("Received message from unrecognized validator", "validatorId", validatorId, "consensus", consensus)
+		return
+	}
+	if schnorr.Verify(crypto.Ed25519Curve, value.PubKey, payload[:offset-64], signature) != nil {
+		consensus.Log.Warn("Received message with invalid signature", "validatorKey", consensus.leader.PubKey, "consensus", consensus)
+		return
+	}
 
 	// check consensus Id
 	consensus.mutex.Lock()
@@ -157,7 +166,7 @@ func (consensus *Consensus) processCommitMessage(payload []byte) {
 	}
 
 	// proceed only when the message is not received before
-	_, ok := consensus.commitments[validatorId]
+	_, ok = consensus.commitments[validatorId]
 	shouldProcess := !ok
 	if shouldProcess {
 		point := crypto.Ed25519Curve.Point()
@@ -174,7 +183,7 @@ func (consensus *Consensus) processCommitMessage(payload []byte) {
 
 		// Broadcast challenge
 		msgToSend := consensus.constructChallengeMessage()
-		p2p.BroadcastMessage(consensus.validators, msgToSend)
+		p2p.BroadcastMessage(consensus.getValidatorPeers(), msgToSend)
 
 		// Set state to CHALLENGE_DONE
 		consensus.state = CHALLENGE_DONE

consensus/consensus_validator.go

@@ -124,13 +124,10 @@ func (consensus *Consensus) processAnnounceMessage(payload []byte) {
 		return
 	}
 
-	// TODO: return the signature(commit) to leader
-	// For now, simply return the private key of this node.
 	secret, msgToSend := consensus.constructCommitMessage()
 	// Store the commitment secret
 	consensus.secret = secret
 
-	// consensus.Log.Debug("SENDING COMMIT", "consensusId", consensus.consensusId, "consensus", consensus)
 	p2p.SendMessage(consensus.leader, msgToSend)
 
 	// Set state to COMMIT_DONE
@@ -154,7 +151,7 @@ func (consensus *Consensus) constructCommitMessage() (secret kyber.Scalar, commi
 	binary.BigEndian.PutUint16(twoBytes, consensus.nodeId)
 	buffer.Write(twoBytes)
 
-	// 32 byte of commit (Note it's different than Zilliqa's ECPoint which takes 33 bytes: https://crypto.stackexchange.com/questions/51703/how-to-convert-from-curve25519-33-byte-to-32-byte-representation)
+	// 32 byte of commit (TODO: figure out why it's different than Zilliqa's ECPoint which takes 33 bytes: https://crypto.stackexchange.com/questions/51703/how-to-convert-from-curve25519-33-byte-to-32-byte-representation)
 	secret, commitment := crypto.Commit(crypto.Ed25519Curve)
 	commitment.MarshalTo(buffer)